Blade mounting



Jan. 17, 1950 A. L. HIGHBERG ETAL 2,494,558

BLADE MOUNTING Filed May 10, 1946 INVENTORS AXEL L. HIGHBERG 6 PHILIP F! NEWCOMB CARL. R. SODERBERG WWW ATTORNEY v .emm

BLADBHOUN'IING "an. .wee'r Newcomb,

SOdQI'DQII, Weston, m mhumu "V W n ion. Y I

' corporation otfDela Application m amslsqm Ne. scare: v -soism-nicLzs ii-Q The present invention relates to "a blade Otherobjects am ss-mama apparent specification, and claims. and from the ,1

mounting for compressor or turbine blades. z

The blades for either compressor or turbines,

are generallyattached to the turbine (1130' by formed blade roots which flt within -a cooperating groove in the This groove may be either i peripheral for circumferential assembly of the blades. or in adirection'parallel to the axis of the disc. inwhich case a separate'groove is provided for each of the formed roots. One-diniculty oi the peripheral groove isthe. tendency for. the disc to spread under the centrifugalload applied by rotation ofthe-disc, which, if not ;prevented, would ultimately release the blades. A feature of this invention is an arrangement by which to prevent spreading oi the disc at its periphery to hold the blades more securely in place.

when the blades are located in a 'circumferehtial groove, the blades are generally inserted at one place in the periphery and are then movedf eircumferentially around the periphery or the I disc into the desired position. To minimize this assembly problem, the disc has been'made up of two parts so that the opposed halves of the disc may be assembled on a row of blades. with this arrangement, the tendency for spreading of the discs at the periphery, thereby loosening or releasing the blades, is evengreater. A feature of the invention is an arrangement for preventing,

have been clamped in position.

In the assembly of turbine or compressor discs spreading of the opposed discs after the blades each blade root may be held by a. pin extending through the disc and the root. Once the hub has, been drilled for one set of-rootsit isnot adapted J for supporting bladeshaving thinner 'orfthicker roots, as where it may be desirable to replace one 1 7 set of blades by another set' using ardiflerent number of blades. A feature of the invention is an arrangement by which the'hubis adapted to support the blades regardless ofthewthickn'ess or the root. 7

Another featureis the use of plates located on from the the disc.

' The completed rotor is made lip-.61 opposed a hub elements 2 and l, which together form, ahub for the support or a row of blades 8. Each blade hasa T-shaped root 8. fitting within a oorresponding shaped groove iii, formed in the. pee

riphery of the hub. As shown, the groove" is 'qformed partly in .each of the hub elements, so that when the elements are assembled, the groove ii is of the proper shape to receive the blade:

roots.

riphery and which are in a positionto engage" with plates i4, preferably segmental, which are positioned on opposite sides of the-hub and extend beyond the periphery oithe hub to engage 5 with the inner radial surfaces on the flanges i2.

-' .The plates I at their outer edges are thick enough to ill! the axial space between the outer T side surface of the hub and the adiaoent'flange I! on the blade root and inthis way wili-pre- J vent spreading of the hub elements adjacent the peripheryvwhere they would be most highly stressed during rotation of the disc.

blade roots, thereby to prevent any spreading of the hub adjacent tothe blade fastening.

Another feature of the invention is the decrease in axial dimension made possible by using a supporting plate to take the bending loads. If the hub itself is made heavy enough to carry the loads the periphery of the hub would, of necessity, be much thicker and would require greater spacing between successive stages of a multistage unit.

by the following claims.

' It will be noted that the diameter of the hub elements 2 and l is slightly less thanthe inside diameter of the cylinder defined by the inneri most surfaces-of the flanges ii'whenltherowot blades is assembled ready to be iaste'ned to the l hub). In this way-thehub elements I and {may v be'placed inposition on the blade roots byaxialassembly of the hub elements. After the hub "elements and the plates ii are in position, they maybe fastened together asby rivets I extend- 1 'ing through the hub elements and the plates.

. It-is to be understood that the invention is not limited to the specific embodiment herein illustrated and described, but may be used in other pirit as ways without departure from its We claim:

V 1. A blade. mounting including a'hubhavingopposed hub elements defining between them a peripheral substantially T-shaped groove, a blade having a T-shaped root fltting in said groove.

and having spaced flanges extending inwardly.

said flanges being spaced apart a distancegreater Each of the blad roots has inwardly extending flanges i2, which are spaced apart a distance enemas beyond the periphery of the hub to engage laterally with the inner side surfaces of the flanges.

2. A blade mounting including a hub having,

opposed hub elements defining between them a peripheral substantially Ii-shaped groove, a blade having a T-shaped root fitting in said groove, and having spaced flanges extending inwardly, said flanges being spaced apart a distance greater than the thickness of the hub adjacent the flanges, and plates fastened to opposite sides of i the hub adjacent its periphery and extending beyond the'periphery of the hub to engage laterally between the flanges and the hub.

peripheral groove, a blade having a T-shaped root fitting in said groove and having spaced peripheral flanges spaced apart a distance greater than the thickness of the hub adjacent thereto and extending inwardly toward the axis of the hub, the outside diameter of the hub elements .-being smaller than the inner periphery oi the 3. -A blade mounting including a hub having opposed hub elements defining between them a peripheral groove, a blade having a root fitting in said groove and having spaced flanges extending inwardly toward the axis 01' the hub, said flanges being more widely spaced than the thickness of the hub adjacent to the flanges, and plates fasbeing more widely spaced than the thickness of the hub adjacent to the flanges, and plates fas-,

tened to opposite sides of the hub adjacent its periphery and extending laterally between the hub and the flanges to prevent spreading of the hub elements, said plates being thick enough to fill the space between the side of the'hub and the inner side surfaces of the adjacent flange,

5. A blade mounting including a hub having opposed hub elements defining between them a peripheral groove, a blade having a root fitting in said gioove and having flanges spaced from the root and extending inwardly toward the axis of the hub, the outside diameter of the hub elements a being smaller than theinner periphery oi. the

flanges on the blade to permit assembly of the hub elements with a row of blades in place,'and a plate fastened to the outer side of each of said hub elements and extending beyond the periphery oi the hub to engage laterally with the inner side surface of. the flange and hold the hub element in place.

6. A blade mounting including a hub having opposed hub elements defining between them a flanges on the blade to permit axail assembly of the hub elements with a row of blades, the groove in the hub fitting the T-shaped root, and a plate fastened to each side of the hub and extending beyond the periphery of the hub to engage laterally with the inner side surfaces of the inwardly extending'fianges to hold the blade in position on the hub.

7. A blade mounting including a hub having a peripheral groove wider at the base than at the outer periphery of the hub, a blade having afroot engaging with said groove and also having spaced inwardly extending flanges the spacing of which is greater than the thickness of the hub adjacent thereto, the inner surface of each flange being at a greater distance from the center of the hub than the radius of the hub and plates on opposite sides of the hub with the outer edges of the plates positioned between the hub and the inner side surfaces of the flanges to prevent spreading of the hub at opposite sides of the groove.

8. A blade mounting including a hub having a peripheral groove wider at the base than at the outer periphery of the hub, a blade having a root filling said groove and being otherwise spaced from said hub, said blade having spaced inwardly extending flanges the spacing of which is greater than the thickness of the hub adjacent thereto, the inner surface of each flange being at a greater distance from the center of the hub than the radius of the hub and plates on opposite sides of the hub and positioned between the hub and the inner side surfaces of the flanges, said plates extending beyond the periphery of the hub.

AXEL L. HIGHBERG. PHILIP P. NEWCOMB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 648,158 Zoelly Apr. 24, 1900 876,971 Junggren Jan. 21, 1908 1,614,145 -Moss Jan. 11, 192':

Heppner Apr. 9, 1946 CARL YR. SODERBERG. 

